sutela@polaris.utu.fi (Kari Sutela) (08/11/90)
I'm currently planning a small application in which I need to be able to calculate the aspect ratio of the default WB-screen. The program would be a simple Turtle-graphics system which would open a window on the WB-screen and serve as an ARexx-function-host accepting turtle-graphics related function calls. Reading through the Includes&AutoDocs I found the variables GfxBase->NormalDPMX and GfxBase->NormalDPMY which, I guess, would be the supported way of retrieving the aspect ratio. The problem is that I don't quite understand the meaning of these fields (the comment in Includes&AutoDocs is a bit vague - what does "1/2 width WB" mean???). Am I correct in assuming that the values tell me how many pixels/meter there are on a non-interlaced lores (320-wide) screen? The values I found (both were betweem 1200 and 1300 - can't remember exactly) on my PAL system seem to support this. Nevertheless, using a lores screen as basis for DPMX seems a bit strange, so I have some doubts about this. So, a short explanation on these fields would be appreciated. BTW, how does one's monitor affect the aspect ratio (or does it? - I just don't seem to understand how video-hardware works :-)? Kari Sutela sutela@polaris.utu.fi